function nuevoAjax(){ 
	var xmlhttp=false; 
	try { 
		xmlhttp=new ActiveXObject("Msxml2.XMLHTTP"); 
	}
	catch(e){ 
		try	{ 
			xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); 
		} 
		catch(E) {
			xmlhttp=false;
		}
	}
	if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
		xmlhttp=new XMLHttpRequest();
	} 
	return xmlhttp; 
}

function invocarCaptcha(img, process){
	var capa=document.getElementById(process);
	var ajax=nuevoAjax();
	capa.innerHTML="Refent codi...";
	
	//
	ajax.open("POST", "process_captcha.php", true);
	ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	ajax.send(0);
	//
	ajax.onreadystatechange=function(){
		if (ajax.readyState==1){
			capa.innerHTML="obtenint...";
			//document.getElementById(img).src = "captcha/loading.png";
			document.getElementById('captcha').innerHTML = "captcha/loading.png";  
		} else 	if (ajax.readyState==4){
			//document.getElementById('captcha').innerHTML = ajax.responseText; 
			var randomnumber=Math.floor(Math.random()*110000)
			document.getElementById(img).src = "captcha/captcha.png?" + randomnumber	;
			capa.innerHTML= ajax.responseText;
		}
	}
}